Degreasing apparatus



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DEGREASING APPARATUS 5 Siesta-Sheet 4 Filed Jan. 15, 1935 Cmrma i'pinlaz Patented Dec. 14, 1937 DEGREASKNG APPARATUS Clarence F. lilinley, Detroit, Mich, assignmto James .lli. Bell, llhiladelphia, Pa.

Application January 15, 1935, Serial No. 1,898

10 Claims.

My invention relates to treatment with so]- vents for such purposes as cleaning and degreesing, and to the use of volatile solvents. Various solvents whose vapors are heavier than air may be used, such as benzine, benzol, and chlorinated solvents like carbon tetrachloride, trichloromethane, tetrachloromethane, dichlorethane, tetrachlorethane, trichlorethylene, and tetrachlorethylene, whosevapors are uninflammable. The articles or work to be cleaned may be treated with the liquid solvent or with the solvent vapor, or both; and in many cases, treatment with hot or even boiling liquid solvent is desirable.

I aim especially at economizing solvent, and preventing or minimizing loss of its vapor from the treating vessel, even with the latter more or less open for the introduction and removal of work. In certain forms of embodiment of the invention hereinafter described, I minimize loss of solvent vapor by employing a treating vessel D that has an opening (or openings) in its upper portion at or near one side (or end) for the introduction and withdrawal of work, but is otherwise substantially closed, so as to exclude air, re-. tain solvent vapor, and prevent drafts into and the vapor at a level or zone substantially below the work opening above referred to, thus limiting the vapor to the lower portion of the vessel, below such level. Thus the closed-in upper portion of the vessel above the level in question affords a draft-free region in which work that has been cleaned in the subjacent solvent (vaporous or liquid) can be dried, and which serves to prevent loss of vapor through the opening(s). Pro- 3 vision may be made for mechanically passing Work into, through, and out of the vessel via the work opening(s) in a definite'or fixed course of traveL-although this is not broadly essential to the invention. In suitable forms of embodiment, such as hereinafter described, my invention affords a compact and efficient machine, wherein large quantities of work can be rapidly, thoroughly, and economically cleaned. Various 5 other features and advantages of, the invention will appear from the description hereinafter ,of species thereof, and from the drawings.

In the drawings, Fig. I is a side view of one form of apparatus suitable for the purposes of my nvention, the main enclosure or treating vessel shown being for the most part in vertical section. Fig. II is a similar view 'of another form of apparatus.

Fig, III shows a vertical section through the Fig. 11 apparatus at right angles to Fig. 11, taken out of the vessel. I also provide for condensing the conveyor chains.

the conveyor system I 3 travels in an irregular, 35

as indicated by the line and arrows HI-HI in Fig. II.

Fig. IV is a view similar to Figs. I and II illustrating yet another form of apparatus.

Fig. V shows a vertical section through the Fig. IV apparatus, taken as indicated by the line and arrows V-V in Fig. IV.

Fig. VI shows a vertical longitudinal section through yet another form of apparatus suitable for the purposes of my invention.

Fig. VII is a. side view of still another form of apparatus embodying my invention.

Fig. VIII shows a vertical longitudinal section. through the apparatus shown in Fig. VII.

Fig, IX is an end view of the apparatus shown 15 in Fig. VII, from the right of Fig. VII.

The apparatus shown in Fig. 1 comprises a sheet metal treating .vessel It that contains the solvent, whether used as liquid or as vapor, and is closed. to exclude air and retain any solvent e vapor that may be present,-purposely or incif dentally,-butis open or apertured at its upper portion, as hereinafter explained, for the introduction and removal of work. In the particular apparatus shown in Fig. I, work is introduced and removed through a single opening it at one side or end of the vessel it, in its (left-hand) side or end wall, andits top wall or root i2 is unapertured. For passing the work in and out of or through the vessels it for treatment, there may. if desired, be a conveyor system it, shown as of an endless chain-and-sprocket type, with a number of work carriers It at-suitable intervals along- Outside of the vessel W,

horizontally elongated loop around guide means supported by a framework it.

In general, work is treated with liquid or vaporous solvent (or both) in the lower portion of the vessel III, while its upper portion serves 40 mainly to prevent or'minimize loss of solvent vapor from the vessel, especially in drying the work after treatment with the solvent. For when the solvent employed is highly volatile .light gasoline or benzine; or when the work is immersed in the solvent while itself still hot or warm; or when the solvent is used hot or even boiled during use; or when the solvent is purposely used in the vapor state; or when the work is allowed to drain or dry in the upper portion of the vessel after treatment with. the solvent;- in all such cases, solvent vapor will be present, and will tend to accumulate to the point of overflowing at the opening ll. When the solvent is to be used hot,-whether as liquid or as vapor,-

it may be heated (and vaporized) in the lower portion of the vessel, by any suitable heating means, such as steam pipes or coils I! there located. As shown in Figs, I and II, the vessel III or wells 20, 2|, 22 separated by "dams consisting of partition-like upward folds 22, 24 of the sheet metal forming the bottom of the vessel. In these several wells 20, 2|, 22, articles or work may be more or less differently treated with the solvent. As here shown, also, the left-hand well 20 is provided with heating means, such as steam piping l8 near its bottom, for heating, vaporizing, or even boiling the liquid solvent in said well.

The escape of solvent .vapor thus or otherwise present in the vessel I2 is prevented not only by the enclosure of its top at l2, and by condensation of vapor from its upper. portion, as hereinafter explained, but also by both introducing and withdrawing the work at the same side of the vessel, at substantially or approximately the same point as represented by the opening so that there can be no drafts of air across or through the top of the vessel II, to cause eddies in the vessel and thus draw or force out the solvent vapor. Loss of solvent vapor can be further prevented or minimized by condensing the solvent vapor from or at a level substantially below the opening II, and thereby limiting the accumulation of vapor in the vessel to its lower portion, below such level. Thus any vapor entering or arising in the draft-free upper portion of the vessel Ill will (being heavier than air) naturally gravitate into the lower portion of the vessel, without danger of escaping through the opening II; and this upper portion of the ve ssel can be utilized to dry work after it has been treated with solvent in the lower portion of the vessel. While the external atmospheric cooling of the upper portions of the vessel walls will .condense vapor in it, yet generally it is preferable to supplement or (largely) replace atmospheric cooling with more effective cooling means, so,

that the vessel ll) need not be so deep as mere atmospheric cooling would require. The particular type and arrangement of cooling means-'- whether internal or external, and whether on one side, two or more sides, -or all around the vessel |||-is broadly immaterial, except that the greater the extent of the cooling means perimetrically of the vessel, the less its extent vertically need be to give adequate. exposed cooling area. The solvent vapor, being heavier than air, will always flow by gravity toward the region or area where it is most rapidly cooled and condensed-Just as if there were an actual outlet for the vapor at such region. However, I have found that a particular general location of the cooling means is peculiarly advantageous in minimizing loss of solvent vapor at the opening H: i. e.', not on the same side of the vessel III as the opening II and the well 2|) where solvent vapor is most profusely generated, but toward or at the opposite side of the vessel from opening H and well 2.. Accordingly, the vessel walls are here shown as (externally) waterjacketed at 22 on three sides, above the wells 2| and 22thus causing .a continual gravity flow or draft of the vapor rising from well 20 away from that side of the vessel, over well 2|, into and across through well 22- just or almost as if there were an actual outlet for the vapor in the right-hand side or end of the vessel I0. The'jacket 28 has an inlet 21 for water or other cooling medium at its lower corneiat mside of the vessel 12 and an outlet at its upper cornerat the other side of the vessel I. (not shown). The pure liquid solvent condensed by the cooling jacket 22 on the vessel has'a plurality of distinct treating compartments walls runs down directly into the wells 2|, 22. Such vapor as condenses on the vessel walls directly above the well 20 (by atmospheric cooling) runs down into well 22. Thus, it will be seen, well 22 normally contains (boiling) hot solvent about up to the level shown in Fig. I; well 2| normally contains relatively cool and pure condensed solvent to the level determined by the lower of dams 22, 24 (preferably the latter), as shown; and well 22 normally contains solvent vapor, as already explained.

As shown in Fig. I, the framework I! includes .uprights 22 against the left handside of the vessel i2 (preferably at its corners), uprights or columns 2| at a suitable distance to the left of the vessel l2, horizontals 22 interconnecting the uprights 2|, 2| a little below the top of the vessel I 0, and sloping rafter-like members interconnecting the upper ends of the uprights 20, 2|. These various members 22, 2|, 22, 22, may be braced at their points of attachment to one another by gusset plates 24.- The upper portion of the vessel ll, including its roof I 2 and the portions of its walls above the horizontal plane indicated by the reference numeral '26, may be made separate from the rest, as a sort of hood 22. This hood 22 may be separately supported, by attachment to the framework |5as by attachment of the roof l2 to a horizontal angle interconnecting the uprights 20 at the front and rear left hand corners of the vessel, and by attachment of the upper portions of the rear and front walls of the vessel (the latter not shown in Fig. I) to the corresponding uprights 20. Thus the hood 22 may be supported from the framework II cantileverwise, virtually independently of the portions of the vessel l0 below the plane 25. As here shown, the portion of the vessel below the plane 25 is divided into sections at'a lower horizontal plane, indicated by the reference numeral 21. 'I'he section 22 between the planes 2!, 21 includes the waterjacket 26, while the lower section 22, below the plane 21, includes the various wells 20, 2|, 22. The hood 26 and the sections 22 and 29 may preferably have external rims of angle sections welded thereto around their upper and loweredges; and when the sections are properly assembled, as shown, these rims may be secured together (vapor-tight) by any suitable means, such as welding, or bolting together with interposed gaskets.

The conveyor system |2 comprises a pair of endless sprocket chains 40, 40, suitably spaced from one another and traveling over a closed course that is determined by guide means mounted on the inner sides of the vessel l0 and on the framework l5; Outside the vessel It, the loop of the conveyor system is determined by pairs of guide sprockets 4|, 42, 42 whose shafts are mounted in suitable bearings on the framework ll. Of these, the upper outer sprockets 4| serve for adjusting the tension or tautness of the sprocket chains 40, 40, their hearing blocks 44 being mounted in vertical guideways 45 in which they may be set at any desired height by means of adjusting screws 46. From the right hand sprocket 42, the conveyor chains 40, 42 with their loaded carriers l4 make an upward pass followed by a reverse or hairpin turn in engagement with guide angles "mounted on the frame members 22, 22, over theupper edge of the vessel II at its opening N. Then the conveyor chains it, til pass downward inside the left hand wall or the vessel to around a hairpin or reverse turn angle guide 56, thus plunging the work on the carriers it into the liquid solvent in the well 203 and drawing it through the solvent to the right and upward. Under the guidance of similar angle bar guides iii 52, 53, and a pair of sprockets d, the conveyor chains (ill make successive upward and downward passes which carry the work into and through the liquid solvent in the well 28 and into and through the solvent vapor in the well 22% From the sprockets 5d, the conveyor chains pass upward to sloping angle bar guides,

55 just below the roof l2. The ends of these guides 55 are bent downward as shown in Fig. I to form suitable guiding curves for the necessary changes in direction of the chains id. As shown in Fig. I, the conveyor system it may be driven by means of an (electric) motor 69 mounted on a bracket (it attached to the framework of the lower vessel section 89, and driving through a speed reducing gearing 62 and a chain-and sprocket connection 63 to a sprocket Gdon the shaft 65 of the conveyor chain sprockets 5d."1t will, of course, be understood that the sprocket to is arranged outside the vessel m, to the rear in Fig. I, and that the shaft 65 penetrates the wall of the vessel section 3? through a suitable bearing or stuffing box 65.

For handling liquid solvent and transferring it from one part of the apparatus to another, as may be required, there is shown a system including a (rotary, centrifugal) pump '10 with a suction line H having connections to the bottoms of the wells 2!, 22 controlled by suitable valves I l2, l3, and a delivery line l5 having connections to or above the upper parts of the wells 20, 2t, 22 (above their normal liquid-levels in ordinary operation) controlled by valves l6, ll, 1d. The suction connection H to the pump 70 is also shown as provided with an external intake connection controlled by a valve id, which may be used when it is necessary to introduce additional solvent into the apparatus to make up for losses. By means of the pump 7d and its connections above described, liquid solvent can be transferred from either of the wells 2!, 22 to any one of the three wells 2d, 25, 22, as may be desired.

In ordinary operation, any liquid solvent over- 7 flowing from well 2! over dam 23 into the well 22 may be periodically drawn out,-so as to keep down the liquid in well 22 to the level shown in Fig. II,and preferably returned to well 28. As a means for doing this automatically by proper operation of pump i8, by the (electric) motor 8!) driving this pump, there is shown an (electric) float switch 33 connected to well 22 and responsive to the liquid level therein for controlling thesupply of (electric) power to the motor 89.

While various modes of operation and use of the apparatus will be apparent from the foregoing description, one preferred mode of operation is as follows:

The wells 28, 2t having been initially filled with pure liquid solvent such as trichlorethylene about to the levels shown in Fig. I, and steam being supplied to the pipes i6, the solvent in well 20 may be heated up to any temperature desired for treating the work, and even kept boiling. Vapor rising from the solvent in well 2% will rise above dams 23, 24 and spread or flow toward the right i (by gravity) into well 22, displacing the (lighter) air. Water (or other cooling medium) willbe circulated through the jacket '26. As the accumulating vapor in the vessel it reaches the cool sites produced by the jacket 26, it will begin to condense, and-will thus be prevented from rising more than about mid-height of this condenser 2d,-and a tortiori, from overflowing or escaping from the open vessel lil;--since the vapor is heavier than air. In other words, the condenser at 28 will draw and keep down the vapor level well below the opening at H leaving a draft-free region or air space in the upper portion of the vessel, as already described.

The endless conveyor system it, driven by the motor carries the work to the right in the lower portion of the enclosure ill, below the vapor level at the condenser 26. In the well 26, the work is initially cleaned of grease and dirt by the (hot) solvent. In the well 2 i, any dirty solvent clinging to the work is rinsed off by the much purer and cooler condensed solvent supplied thereto from the condenser 26. Having been heated up in well 21-3 by the hot solvent and cooled off again considerably in well it, the work enters well 22 cooler than the vapor in the latter, which therefore condenses on the work and thus rinses it exceedingly clean of any last traces of grease. Ascending from the well 22, the work dries ofi by the time it leaves the vessel ill via the opening. The clean work can be removed from the carriers id and replaced with other work to be cleaned-or the carriers it themselves may be removed and replaced with other carriers already loaded with dirty work-while the carriers aretraveling along the lower external run of the conveyor system, between the sprockets and 43. v

During the return travel of the carriers M with their loads of clean work from the condenser 26 upward and then to the left and upward beneath the roof l2, above the vapor level at the condenser 26, there is ample opportunity for solvent to drain and dry off from the work, which will have been thoroughly heated up by contact with the solvent vapor in the well 22. This is especially desirable in the case of work having recesses in which solvent from the wells iii, 22 may collect, because the dwell of the cleaned work in the upper part of the vessel permits such solvent to evaporate there, instead of being carried out into the atmosphere and lost. Being heavier than air, the solvent dripping or evaporating from the work during its travel upward and to the left falls or sinks by gravity into the bulk of solvent vapor in the vessel It), without any, appreciable loss at the opening ii, since drafts which might carry the vapor out of the vessel throughrthe opening it are precluded by the enclosure of the upper portion of the vessel on all other sides.

The apparatus shown in Figs. II and III differs from that of Fig. I in that the conveyor system Ida does not actually leave the enclosure lOa, but instead makes a downward pass just inside theleft-hand side or end wall of the enclosure, whichhas an opening I to with a door so through which the clean work (or the carriers H loaded therewith) can be removed from the conveyor and replaced with dirty work. The

door 90 is shown closed, but may be normally kept open during the ordinary operation of the apparatus. The enclosure It) is shown as made in lower and upper sections 9|, 92, the latter of which can be lifted off when detached from vapor level at the condenser 26, that prevents escape of solvent vapor at opening Na and allows of drying the work during its return travel to the left above the vapor. The action during the travel of the work to the right below the vapor level is like that in Fig. I. The well 20 contains (electric) heating elements I6a, and the guides 4 5|, 53 of Fig. I arereplaced by (idle)'. sprockets 1 BIa, 63a.

To provide for adjusting the tension of the conveyor chains 40, 40, the shaft 30 of two of the sprockets that guide their upper, return run may be made horizontally adjustable. For this purpose, the shaft 96 extends out through slots 91 in the enclosure walls to bearings .03 that are adjustable along guideways 33 outside the enclosure, by means of adjusting screws I00. The

enclosure walls may be strengthened with ex-:

section 9| has a horizontal angle frame IN on which the condenser 26 engages, and has angle corner braces and legs I02 by which it is supported from the floor. Additional underframing for the section III includes angles I03 that support the bottoms of the wells 20, 2|, 22. The conveyor driving motor 60a and its speed reducer 62 are shown mounted on horizontal angle framing I04 attached to the legs I02 near their lower ends. The provisions for transferring solvent include a valved return pipe I05 from the bottom of well 22 to well 20, and a (gear) pump I06 with a valved suction connection I01 to the bottom of well 2| and a delivery connection I08 delivering just above well 20. The connection I01 also includes a valved external intake I08 suitable for the introduction of additional solvent solvent wells, a boiling well 20 and a purified solvent rinse well 2|, over which is the condenser 26. This particular apparatus is especially adapted for cleaning strands or sheets-as of wire, sheet metal, wire cloth or screening, etc., etc.,--which enters and leaves the vessel or enclosure I b through horizontal entrance and exit slots I I0, I in the left-hand end of the'enclosure near its top,-the upper portion of the enclosure projecting or overhanging a little beyond the lower portion at this end. The entering work passes from a supply or approach guide roll IIZ (which is mounted in bearings II3 on an angle bar frame projecting to the left from the enclosure IOb) between two spring-actuated scrapers II3X, II3Y which rubofl loosely adherent dirt; through the entrance opening IIO; over and around a guide roll III and downward nearly to (or into) the liquid solvent in the well 20; under and around a guide roll II! in well 20; up. over and around a guide roll II6 over the left-hand end of well 2|; down under and around a guide roll III that-dips into the liquid solvent in well 2|; upward and to the left through the upper portion of the enclosure I0; and out through opening III, and over and around an externalguide roll lll'whose trunnions or axis is mounted in bearing brackets II3 attached to the outer left-hand wall of the enclosure. The work may be drawn through the apparatus by any suitable means, which need not necessarily be the roll I" or other part of the apparatus itself; "As shown, the guide roll H in well 20 has its axis bearings I20 mounted for vertical adjustment along ways I2I, so that the sheet material or work may either run through the liquid in well 20 or pass over it through the vapor.

As shown in Figs. IV and V, the vessel or enclosure Ilb is divided into lower and upper sections I22, I23 very much as in Figs. II and III. The lower section I22 includes wells 20, 2| and condenser 20, while the upper section I23 includes the openings IIO, III and the supporting means for the bearings of all the internal roll axes,as well asfor the bearings of the external roll III. For this purpose, there are angle bar side frames Ill, I23 whose upper horizontal angle members I26, I 26 are welded to the upper flanges of horizontal angle bars I26, I26 which are themselves welded to the inner sides of the walls, of the upper vessel section or cover I23.

As shown in Figs. IV and V, the apparatus includes a solvent storage tank I30 underneath the well2I, with a valved pipe connection I3I to said tank from the bottom of well 2|. For returning solvent from tank I30 into the vessel I0, there is .a (gear) pump I32 with a valved suction connection I33 to the bottom of tank I30 and a delivery connection I34 into the vessel I0 just above well 20. There is also shown a thermometer I36 extending into well 2| and out through the side of the vessel I0, to allow the temperature of the solvent in the well 2| to be read whenever desired during the operation of the apparatus. As shown, the heating pipes or coils I6 are mounted on a cover I36 detachably secured over an opening in a lateral wall of well 20, so that they can be removed and the well more easily cleaned.

In Figs. IV and V, various parts and features have been marked with the same reference numerals as in Figs. I-III,with an annexed letter, where such distinction appears necessary,as a means of dispensing with repetitive description.

In this apparatus, besides the draft-free space in the upper portion of the enclosure or vessel I0b, above the vapor level at the condenser 26, and the draft of solvent vapor from well 20 toward condenser 26 and away from openings IIO, III, the traveling work itself offers an obstacle to drafts toward the left which might tend to carry vapor to the openings IIO, II I. This is especially so in the case of sheetmetal or other impervious material, which act as a condensing blanket and doubly curtains off or occludes the left-hand end of the enclosure by its downward run between rolls I I4, 5 and its upward return run between rolls I I1, 8. The general action and conditions in the apparatus are similar to those in Figs. I-IlI."

The apparatus shown in Fig. VI is likewise specially adapted for treating strands or sheets of wire, wire weave, screening, or sheet metal,

etc., etc. Here, however, the work enters and leaves the vessel IIIc through a common slot I40 in its top or roof I2, which is at the opposite end of the vessel I from the well 20 where the solvent is heated and vaporized. In this in-- stance, the condenser 26 entirely girdles the vessel I0, and a trough or gutter I4| extends around most of three sides of the vessel I0, to catch solvent condensing on the vessel walls above well 20. This trough |4| left and delivers the condensate into the purified solvent rinse well 2|.

The approaching work ascends and makes a hairpin turn over a (lower) guide roll I42 mounted in hearings on a bracket I43 on the cover I2, and then descends through opening I40 into the vessel I0. Descending into the liquid solvent in well 2|, it passes under and around a guide roll I44, and thence makes an upward-sloping run to the right over well 20', to a guide-roll I45 in the right-hand end of the vessel, about on a level with the top of condenser 26. It then makes a horizontal run to the left in the top of the vessel I00, above the vapor level therein as determined by condenser 26, to a guide roll I46. Passing under and around the roll I46, the work passes up through opening I40 to an (upper) guide roll I41 mounted in bearings in bracket I43, and then passes over and around this roll I41.

In its pass from roll I44 to roll I45, the work passes between two spring-actuated rubbers I48, I49 which rub oif or loosen any dirt clinging to it, so that the thus bared metal may be more efiectively acted on by the solvent condensing on the metal over well 20. In its travel from roll I45 to roll I46, the work is above the vapor, and the solvent clinging to it drips oil or evaporates, and gravitates (being heavier than the air in the top of the vessel I0) into the vapor beneath. Thus the work emerges at I40 perfectly clean and dry, and all loss of solvent is avoided. Indeed, the two runs of the relative cool work from roll I44 to roll I45 and back to roll I46 form a double condensing blanket interposed and occluding the interior of the enclosure illc between well 20 (where solvent is vaporized) and opening M0, effectually preventing any drafts, or eddies in the vessel I0 from carrying vapor upward to opening M0. In general, the action and conditions in this apparatus are similar to what takes place in Figs. I-V.

As shown in Fig. VI, there is an'opening in the enclosure roof or cover I2 that can be closed by means of a sliding cover I 50. This opening facilitates inspection of the interior of the apparatus, and also afiords convenient access for cleaning, passing sheets or strands around the guide rolls, etc.

In Fig. VI, various parts and features are marked with the same reference numerals as in Fig. I (with added letters where such distinction appears necessary) as a means of dispensing with repetitive description.

The apparatus shown in Figs. VII, VIII and IX resembles those of Figs. IV, V and VI, being especially adapted for cleaning strands or strips of wire or of sheet metal, wire cloth or screening, or other sheet material. The strands or strip to be treated may enter and leave the vessel or enclosure Illd through a common slot M in its top or roof I2 at its left-hand side or end, above the solvent heating or boiling well 20, around (idle) guide rolls II2d, ||8d mounted side by side in or above the opening I40d. Referring especially to Fig. VIII, it will be seen that slopes downward to the from the supply-or approach roll I I2d. the course of the work is like that in Fig. IV, except that from guide roll IIId in well 2| the work passes up around and over a superiacent guide roll IIID (shown as about level with the top of the water-Jacket condenser 26), on its way to the exit guide roll 011. As here shown (Figs. VII and VIII), the bottom wall |5| of the vessel Id between the wells 20 and 2| extends on a slope parallel with the run of the work between'rolls HM and H611, and in close proximity thereto,- so that the solvent overflow from well 2| down the sloping spillway wall |6 I washes this ascending run of the work, preferably on both its under and upper sides. To minimize friction, actual contact of the work with the spillway |6| may be avoided: as shown, the clearance between them is exaggerated for the sake of clearness of illustration. Besides the heating means I6 for the solvent "in well 20, means are preferably provided for also heating the (purified) solvent As shown in Fig. VIII, the condenser 26 and the trough or gutter I4 Id for catching the condensed solvent extend all the way around the vessel I0d on all sides. This condensate trough I4Id lies directly beneath the condensing jacket 26, and is open into the interior of the vessel I0d through a slot in the vessel wall. The trough I4Id has an inward flaring or projecting upper portion or lip formed by deflection of the vessel wall (below the slot) inward beyond its general plane. From this trough I4|d the condensate may ordinarily overflow or run ofi into the well 2i, as through notches I55 in the inward-sloping upper portion of the inner trough wall, directly over the well 2|. Directly under the well 2| and its heating jacket l52, there is shown a purified solvent. storage tank or reservoir I30d, preferably of sufficient capacity to contain all the solvent normally used in the vessel 50d. This reservoir |30d may have a valved pipe connection I3 Id to the bottom of well 2|, and also a valved "by-pass pipe connection |3ID to the bottom of the solvent trough Mid, When either of these connections is open sufiiciently, all or part of the condensate runs into reservoir I30d.

The ordinary operation of the apparatus of Figs. VII-IX resembles that of the Figs IV and V apparatus, and need not be specially described. However, the heating of the solvent in well 2| allows of treating the work with purified solvent at any temperature up to boiling; and the contact of the solvent flow from 2| to 20 with the work travelling from 20 to 2| washes ofi most of the dirt from the work before the latter reaches well 2|, so that contamination of the solvent in the latter is prevented or minimized. In other words, most of the dirt accumulates in well 20 and only a very little in well 2|. When cleaning of well 26 (or/and 2|) becomes necessary, it is only necessary to open the valved connection I 3ID and heat the solvent in wells 20 and 2| to boiling, thus distilling practically all the solvent into trough Id and reservoir I30d, whereupon the apparatus may be opened, and the wells 20 and 2| thoroughly cleaned out.

Thereafter the pure solvent may be returned from reservoir I30d to well 20 by means and connections similar to those of Figs. I and II, including a return pipe I05d from the bottom of reservoir mm to that of well 20, with valves I56, I51 therein, and a pump 10d with suction connection 1Id to pipe I05d between valves I56 and I51, and a delivery connection 15d, with an anti-return check valve I58 therein. There is also a valved return pipe I05D from the bottom of well 2I to well 20, and a valved draw-01f or drainage connection I59 from the pipe I05d aforesaid. As shown, the pump 10d is a centrifugal pump with its axis and shaft upright, and is driven by an (electric) motor I60 directly connected to the shaft.

6 Purification of the solvent as just described can be effected more rapidly than in Figs. I-V, because with this apparatus solvent can be concurrently distilled from both of wells 20 and 2| by their respective heating means I6 and I52. Whereas in Figs. I-V only well 20 with its heating means I6 can be used to vaporize the solvent; for in Figs. I and 11, both of Wells 2I and 22 are needed to contain the pure condensate when practically all the solvent in well 20 is boiled off; and in Fig. IV, well 2| must be used to collect the condensate that runs into reservoir I30.

However, Figs. VII and IX show other means for purifying the solvent used in the apparatus,

arranged conveniently alongside the vessel I0d. For this purpose, there is an evaporator or boiler I62 provided with heating means such as a bottom jacket I83 with inlet I64 and outlet I65 for steam or other heating medium, and connected to the delivery pipe 15d of the pump 10d. The solvent vapor generated in the boiler I62 passes up through a pipe I66 into a water-tu surface condenser I61 conveniently mounted above the top of the boiler; and the condensed and purified solvent is returned into the vessel Illd from the bottom of the condenser I61 through a pipe I 68, at a point above the well 2I and the work-run between the rolls I I5d and I I6d. Water or other cooling medium may be circulated through the tubes of condenser I61 via inlet and outlet connections I10, III. The grease and dirt accumulating in the bottom of boiler I62 may be drawn off from time to time through a valved drainage connection I12, shown as extending up through the heating jacket I63.

Provision may be made for controlling or regulating the action of the pump 10a automatically according to the liquid solvent level in the boiler I62. For this purpose, a float switch responsive to the liquid solvent level may be used. As shown, the float I15 is in a separate chamber I16 having connections I11, I18 to the liquid'and vapor spaces of the boiler; and the switch I19 operated by the float makes and breaks the electric power supply circuit 180 to the pump motor I60. A gauge glass I8I for showing the liquid level in boiler I62 is shown connected between the float chamber connections I11, I18, with the usual shut-ofi valves to be closed when the gauge glass requires cleaning out, or if it should break. The float I15 closes the circuit I80 and starts the pump 10d to transfer solvent from tank I30d to boiler I62 whenever the liquid level in the boiler falls below a certain level; and when this liquid level has been restored, the float opens this circuit and stops the pump. The power circuit I80 may also be provided with a manual control Switch I83. I

I62 and condenser I61-may be operated or used in various ways, either intermittently, while cleaning of work in the apparatus is suspended, or continuously while work is being cleaned.

For example, to purify the solvent while treatment of work is suspended, the valved connection I3ID from trough I4Id to storage tank I30d may be left closed, and the connection I3Id opened to drain the well 2| freely into the storage tank [3011. When all (or substantially all) the solvent in well 20 has been distilled over into well 2! and run in tank I30d,-thus washing out the bottom of well 2I,the valved connection I3Id and the power switch I83 may be closed, and the solvent in tank I30d thus passed through the still I62, I61 and returned into well 2I while well 20 is being cleaned out.

Or to purifythe solvent continuously while treatment of work goes on uninterrupted, the valved connection I3 Id may be opened sufficiently to let the solvent in the bottom of well 2I run off slowly into tank I30d while overflow at I5I continues,thus allowing dirt in the bottom of well 2I to run into the tank I30d,while valved connection I3ID remains closed. In this way, the solvent in well 2I will be continuously purified and returned to fall on the run of work between rolls II5d and I I6d and assist in washing it; and dirt will accumulate only in well 20. This mode of operation is especially adapted to the treatment of work with adherent greasy dirt that requires prolonged soaking in well 2| to loosen and remove it.

In Figs. VII-IX, various parts and features are marked with the same reference numerals as in other figures,--with an added letter where such distinction appears necessary,as a means of dispensing with repetitive description.

Having thus described my invention, I claim:

1. Apparatus of the character described, for treating articles or work with volatile solvent whose vapor is heavier than air, comprising in combination a treating vessel or enclosure adapted to contain volatile liquid solvent and its vapor, and apertured and open for the introduction and withdrawal of work directly into and from its upper portion at one side thereof only, but otherwise covered over and substantially closed, so as to prevent drafts into and out of the vessel while at the same time permitting introduction and withdrawal of work at the work opening above referred to; cooling means for maintaining in the vessel a cool vapor-drawing condensing zone at a level substantially below its work opening above referred to, so that the closed-in portion of the vessel above said level affords a draft-free region in which work cleaned with the solvent below said level may be dried before Withdrawal from the vessel, without resulting loss of solvent vapor through the opening; and an endless conveyor traveling a course from the opening above referred to down below said condensing zone, and also through said drying region and back to the work opening.

' 2. Apparatus of the character described, for treating articles or work with volatile solvent whose vapor is heavier than air, comprising in combination a treating vessel adapted to contain volatile liquid solvent and its vapor, and apertured and open for the introduction and withdrawal of work directly into and from its upper portion at one side thereof only, but otherwise covered over and substantially closed, so as to prevent drafts into and out of the vessel while at the same time permitting inor enclosure vessel a cool vapor-drawing condensing zone at a level substantially below its work opening above referred to, so that the closed-in portion of the vessel above said level affords a draft-free region in which work cleaned with the solvent below said level may be dried before withdrawal from the vessel, without resulting loss of solvent vapor through the opening; and means for passing and guiding work into, through, and out of the vessel,

covered as aforesaid, via the work opening abovereferred to, with travel through said drying region and also below said condensing zone. I

3. Apparatus of the character described, for

treating articles or work with volatile solvent whose vapor is heavier than air, comprising in combination a treating vessel or enclosure adapted to contain volatile liquid solvent and its vapor, and aperturedand open for the introduction and withdrawal of work directly into and from its upper portion at one sidethereof only, but otherwise covered over and substantially closed, so as to prevent drafts into and out, of the vessel; cooling means for maintaining in the vessel a cool vapor-drawing condensing zone at a level substantially below its work opening above referred to, so that the closed-in portion of the vessel above said level affords a draft-free region in which work cleaned with the solvent below said level may be dried before withdrawal from the vessel, without resulting loss of solvent vapor through the opening; and means for passing and guiding work into, through, and out of the vessel via the work opening above referred to, in a course away from the opening through the lower portion of the vessel and returning thereto through the upper portion of the vessel, above the level of said condensing zone.

4. Apparatus of the character described, for treating articles or work with volatile solvent whose vapor is heavier than air, comprising in combination a treating vessel or enclosure adapted to contain volatile liquid solvent and its vapor, and apertured and open forthe introducthe vessel, without resulting loss of solvent vapor through the opening; and an endless conveyor entering the vessel through the lower part of said opening and leaving it through the upper part thereof, and travelling in an elongated unloading and loading loop outside the vessel, and within the vessel travelling away from the opening through the lower portion of the vessel and returning to the opening through the upper por;

tion of the vessel, above the level of said condensing zone.

5. Apparatus of the character described, for treating articles or work with volatile solvent whose vapor is heavier than air, comprising in combination a treating vessel or enclosure adapted to contain volatile liquid solvent and its vapor,

and apertured and open for the introduction and "withdrawal of work directly into and from its upper portion at one side thereof only, but otherwise covered over and substantially closed, so as to prevent drafts into and out of the vessel, said vessel having in its lower portion a plurality of wells, one at the same side of the vessel as its work opening. above referred to, and another further away from said side; means for heating and vaporizing liquid solvent in said first-mentioned well; and condensing means over said other well, at a level substantially lower than said work opening, for drawing away and condensing the solvent vapor evolved in the well first above" mentioned, and thereby supplying said other. well with purified liquid solvent and keeping down the vapor levei in the vessel substantially to saidmeans, so that the closed-in portion of the vessel above said level affords a draft-free region in which work. cleaned with the solvent below said level may be dried before withdrawal from the vessel, without resulting loss of solvent vapor through the opening.

6. Apparatus of the character described, for treating articles or work with volatile solvent whose vapor is heavier than air, comprising in combination a treating vessel or enclosure adapted to contain volatile liquid solvent and its vapor,

and apertured and open for the introduction and withdrawal of work directly into and from its upper portion at one side thereof only, but otherwise covered over and substantially closed, so as to prevent drafts into and out of the vessel; cooling means for maintaining in the vessel a cool vapor-drawing condensing zone at a level substantially below its work opening above referred to,'so that the closed-in portion of the vessel above said level affords a draft-free region in which work cleaned with the solvent below said level may be dried before withdrawal from the vessel, without resulting loss of solvent vapor through the opening; and means for passing sheet material into, through, and out of the vessel via the work opening above referred to, in a course within the vessel interposing between the said work opening and the region of evolution of solvent vapor in the lower portion of the-vessel.

7. Apparatus of the character described, for treating articles or work with volatile solvent whose vapor is heavier than air, comprising in combination a treating vessel or enclosure adapted to contain volatile liquid solvent and its vapor,- and apertured and open for the introduction and withdrawalof work directly into and from its upper portion at one side thereof only, but otherwise covered over and substantially closed, so as to prevent drafts into and out of the vessel, said vessel having in its lower portion a plurality of wells, one at the same side of the vessel as its work opening above referred to, and the other further away from said side; means for heating and vaporizing liquid solvent in one of said wells;

and cooling means for maintaining in the vessel a cool vapor-drawing condensing zone at a level substantially below its work opening above referred to, so that the closed-in portion of the vessel above said level afiords a draft-free region in which work cleaned with the solvent below said level may be dried before withdrawal from the treating work with volatile solvent whose vapor is heavier than air, comprising in combination an air-excluding treating vessel or enclosure open to the atmosphere for introduction and removal of work, and provided with means ailfording separate solvent wells in said vessel, with an intervening spillway, and permitting accumulationlof liquid solvent in one oi said wells higher than the solvent level in another and overflow 01 excess from the one well via said spillway into the other well, and also provided with means above said wells, but below where the vessel is open as aforesaid, for retaining and condensing solvent vapor evolved in the vessel and thus preventing its overflow from the apparatus, and

for thereby supplying said overflowing well with the solvent level in another and overflow or excess from the one well via said spillway into the other well, and also provided with means above said wells for retaining and condensing solvent vapor evolved in the vessel and thus preventing its overflow from the apparatus, and for thereby supplying said overflowing well with liquid solvent; and means for passing work to be treated through the vessel and upward along said spillway from the well receiving the overflow to the overflowing well and through the liquid solvent in the latter, so that the ascending work may be washed by the downflow of solvent on the spillway and contamination of the overflowing well from the work thus minimized.

10. Apparatus of the character described, for treating work with volatile solvent whose vapor is heavier than air, comprising in combination an air-excluding treating vessel or enclosure open to the atmosphere for introduction and removal of work, and provided with means affording separate solvent wells in said vessel, and permitting accumulation of liquid solvent in one of ,said wells higher than the solvent level in another and overflow of excess from the one well into the other well, and also provided with means above said wells ior retaining and condensing solvent vapor evolved in the vessel and thus preventing its overflow from the apparatus, and for thereby densate from said distilling means to said overflowing well.

CLARENCE F. DINLEY. 

